Set Field [Table1::Field ; Table2::Field]
won't work unless there is a valid relationship between the current record in Table1 linking it to the correct related record in Table2. Since you are creating a new record. All such foreignkey fields are empty until you enter data into them and thus it is not yet linked to any related record and the set field steps fail to copy any data.
The way to get around this is to use set variable to copy the relevant data into variables before creating the new record, and before changing layouts to a layout based on the second table. Then you use set field to copy the data from the variables into the fields of the new record.
Thank you - I had to attend to some other business when I received this answer, but when I came back to it, I used your advice and it worked perfectly and simply. I appreciate your prompt and kind attention to help me.